Who is the second-best starting pitcher on the Cardinals roster right now?

Going into the offseason, the St. Louis Cardinals accomplished multiple things:

1. Signing a front-end starter in Sonny Gray.
2. Shoring up the back end of their rotation with Lance Lynn and Kyle Gibson.
3. Bullpen overhaul, bringing in two new high-leverage relievers and multiple upside arms.
4. Clearing up some of the logjams with their position player group.
5. Bringing in some new voices in both the front office and coaching staff.

While this in itself was a lot to accomplish in one offseason, most Cardinals fans are left disappointed at the lack of a second front-line starter to pair with Gray, who was runner-up in American League Cy Young voting in 2023.

While we can spend time debating how big of a failure that was, and who they should have or could have gone out and acquired, barring a surprise move, the Cardinals will enter the season with a rotation of Gray, Lynn, Gibson, Miles Mikolas, and Steven Matz...or perhaps a young arm like Zack Thompson or Matthew Liberatore if an injury arises.

So, that begs the question, who is the second best starter on this staff?

Trying to identify the Cardinals' "second-best" starting pitcher

Let's be clear, the Cardinals do not have a "number two" starter on their staff, someone who can pair with Sonny Gray in a playoff series against the best rotations in baseball. We can debate if Gray is an "ace" or not, but it's clear that he's someone who belongs at the front end of a contender's rotation. There are very few starting pitchers who I think are true "aces" in today's game, and then a larger group of pitchers can go toe-to-toe with the other top pitchers in the game.

Look at the Texas Rangers last year. Jordan Montgomery and Nathan Eovaldi were not aces. I get they technically had Jacob deGrom and Max Scherzer, but deGrom did not pitch in the postseason and Scherzer's impact was not as important as Montgomery and Eovaldi. What's also true is nobody is going to call Montgomery or Eovaldi an ace, and I haven't seen many people calling them top-25 starters in baseball.

So yes, Gray is certainly good enough to lead a playoff rotation, or at least be one of those two guys. Would I prefer them to also have a true ace as well like Corbin Burnes, Spencer Strider, or Gerrit Cole? Uh, yeah! But that player is not available right now...so I certainly wouldn't be opposed to them adding a Montgomery or Dylan Cease to beef up that front end of the rotation.

But alas, once again, this is the rotation they are committing to for the beginning of the season. If they are in contention at the deadline, I'll be shocked if they do not upgrade this group. We've had plenty of discussion over how "good" this rotation is, but for now, let's just try to identify who that "second-best" arm is as of today.

First, let's just break down the counting stats from last season.

On the surface, there's not a ton separating these guys, and I think that's mostly true. All of them profile as number four or number five starters right now, so the trick here will be identifying who has the most "upside", someone who can if things go right, play up to a higher role than the rest of these guys.

To be clear, I don't think any of them can be a true number two starter on this staff, but could one rise above the rest and be the clear number two out of the five? I think so.

If I had to do a quick process of elimination, I would probably rate Mikolas as having the lowest upside of the group. His strikeout percentage is by far the worst of the bunch, he led the league in hits allowed by a wide margin, and his stuff has been diminishing. I embedded a tweet below from BrooksGrate that you have to click on to see Mikolas' ranking, but his sinker was the 20th "least valuable pitch" in baseball last year.

Can Mikolas stabilize himself as a fine back-end of the rotation guy? Sure, but I do not see how he outperforms all three of the other arms in this bunch.

I could see arguments for Gibson, Lynn, and Matz as that "second-best starter", but when it comes down to it, I'd cross off Gibson from the running as well. He's a guy who I feel very confident in being a really good number four or number five starter, giving the Cardinals a chance to win more often than not, but not a guy who's going to "outduel" anyone on a given night.

That leaves Lynn and Matz as the two front-runners in my book for the second-best starter. Talent alone, I'd pick Matz in this conversation, as he's a guy who strikes guys out at a similar rate as Lynn but also doesn't have the major home run issue that Lynn had last year.

Matz, in his seven starts returning to the rotation before his season-ending injury last year, posted a 1.86 ERA, crediting his refined change-up, newfound comfortability with his curveball, and pitching with more of an edge each time out.

If Matz resembles that version of himself in 2024, he's easily the second most talented starter on this staff and the guy I'd slot in as their number two currently. The problem with Matz though has been his inability to stay healthy, especially during his Cardinals tenure.

For Lynn, a big factor in his upside for 2024 will be improving his league-worst HR/FB ratio last year, which was a mind-boggling 19%. HR/FB ratios can be a bit volatile year to year, similar to forced turnovers in the NFL, so some positive regression would go a long way toward helping Lynn improve from a production standpoint.

Another area of improvement for Lynn is his BB%, which also took a massive spike in 2023 (8.3%). While his career BB% is not far off at 8.2%, he has found a lot of success in recent years by limiting walks, allowing just 3.7% in 2022 and 7.3% or lower from 2019-2021. Walking a lot of hitters and giving up the most home runs in baseball will hurt you in a massive way.

All in all, Matz appears to be the clear-cut second-most talented starter on this staff in 2024, and his health can go a long way toward helping the rotation be much better than it was in 2023. Matz pitching like a true number three starter would actually go a long way for St. Louis, and if Lynn can do that too, they are in a lot better shape than it seems. If not, the Cardinals have one front-line starter and four back-of-the-rotation guys, and that's not an easy way to win ballgames.